Still no wreckage, and reports now say that military authorities
tracked the missing plane for nearly 500 miles after contact was
lost with air traffic control.

I hate to say it, and to violate my own anti-speculation rule,
but it’s looking more and more like something very strange, and
possibly nefarious, is behind the disappearance. A hijacking,
perhaps, that ultimately ended in disaster somewhere in the South
China Sea.

Investigators also say the plane’s transponder signal — a
location and altitude signal that is tracked by air traffic
controllers on the ground — disappeared suddenly. This would
indicate a sudden loss of power, as would happen during an
inflight explosion or breakup, for instance. But if that were the
case, why is the wreckage not where it should be, and what’s to
explain the 500-mile continuation? Was there a complete loss of
electric power, rendering the transponder inoperative, after
which the aircraft continued on for many miles? Or was the device
switched off intentionally during a hijacking?

Unfortunately it could be weeks or even months before we have a
solid idea of what happened. And tempting as might be, we should
be careful not to speculate too broadly. Almost always the
earliest theories turn out to be at best incomplete; at worst
totally wrong. Seeing how little evidence we have at the moment,
any theories are, for now, just guesses.

All we know for sure is that a plane went missing with no warning
or communication from the crew. That the crash (assuming the
plane did in fact go down) did not happen during takeoff or
landing — the phases of flight when most accident occur —
somewhat limits the possibilities, but numerous ones remain. The
culprit could be anything from sabotage to some kind of bizarre
mechanical problem — or, as is so common in airline catastrophes,
some combination or compounding of human error and/or mechanical
malfunction.